I want to give y'all a heads-up on a new source for Salvadoran chow - in Towson, no less. It's in a rather unexpected location - a little place called Seafood Bistro at 123 York Road (near Jiffy Lube and Pizza Palace, if that rings a bell, and in the location where Towson Kabob used to be). Seafood Bistro opened fairly recently and I can't attest as to the quality of their seafood menu, but a few days back I was walking past, decided to check out their offerings, and saw that they now are serving Salvadoran items!
It's a standard range of tamales, pupusas, entrees, pasteles, and an assortment of bebidas (including a great horchata). I was very pleased with everything I tried (corn tamale, refried bean tamale, loroco, bean, and pork-and-cheese puposas, and plantains-with-sour-cream). Everything was, as you'd expect, inexpensive.
At any rate, check this place out - I don't know how it compares to the Fells Point Salvadoran places but it's nice to have an option closer to (my) home.